Sample Problem 9 A bob of mass m is suspended by a light string of length L. It is imparted a horizontal velocity vo at the lowest point A, such that it completes a semicircular trajectory in the vertical plane with the string becoming slack only on reaching the topmost point C. The ratio of the kinetic KB energies at B and C is Kc (a) 3:1 (b) 1:3 (c) 5:2 (d) 2:5